Universal Industrial Gases, Inc...Rare Gases - Neon, Krypton, Xenon Properties, Uses, Applications Interesting Facts and Information about the "Rare Gases": The so-called "rare" gases Neon (Ne), Krypton (Kr) and Xenon (Xe), are present in air in very low concentrations. Like the other "noble" or "inert" gases, helium (He), argon (Ar) and radon (Rn), Neon, Krypton and Xenon remain in the air because they do not combine with other materials to form solid or liquid compounds. All of these gases are monatomic. Neon, Krypton and Xenon are valued for their light emitting properties when electrically charged. Krypton and Xenon are also valued for their total inertness coupled with high molecular weight (83.80 and 131.30, respectively). Krypton and Xenon are about two to three times as heavy as argon (molecular weight 39.95) and approximately three to four times as heavy as nitrogen (molecular weight 28.0) which is used as in inert gas in many applications, but is not a true inert gas.

These properties are put to good use in multi-pane windows to reduce heat loss due to convection between the panes; and in light bulbs, where their high molecular weight slows evaporation of the hot tungsten filament, leading to longer useful operating life. Krypton and Xenon have also been considered for a more exotic application - as the propulsion gas for deep space exploration using ion engines. Neon, Krypton and Xenon can be economically recovered by adding additional purification steps in large air separation plants or ammonia production plants (which use large amounts of air as a raw material). The boiling point of Neon is significantly lower than nitrogen (lower than all the gases except helium and hydrogen). It can be used as a very low temperature working fluid in refrigeration cycles. Neon can be recovered from large nitrogen plants as well as multi-product air separation units. Krypton and Xenon have higher boiling points than oxygen, from which they can be separated by distillation in air separation plants. When these products are recovered from ammonia plant purge gas, the neon must be separated from hydrogen and nitrogen, and the krypton and xenon from methane. All of the naturally inert or "noble" gases are members of "Group 18" of the Periodic Table.

Group 18 materials have a complete outermost electron shell; the "valence" shell that is highly involved in the formation of compounds. Moving down the Periodic Table from Helium, to Neon, Argon, Krypton, Xenon and Radon, the valence shells are located further from the nucleus, above the previous element's valence shell. Helium has two valence electrons, the other noble gases have eight. Rare Gases Applications and Uses for Neon (Ne), Krypton (Kr) and Xenon (Xe): Lighting: Neon is commonly recognized as the gas that produces the glow in "neon" lights (which often contain other gases as well). Neon's natural red color can be turned into a wide range of effective decorative lighting colors by mixing neon with other gases, by using colored glass tubes or by depositing fluorescent powder coatings inside the glass tubes. Neon is also used to produce a red glow in indicator lamps and lasers. Krypton is used in halogen sealed beam headlights to increase light output by allowing thinner filaments to be used with acceptable useful lifetimes.

Krypton is also used in in lasers, in particular mixed with fluorine to create an "excimer" mixture that is a precursor to a molecule which exists in the excited state but not in the ground state. In excimer lasers, the gas mixture is pulsed to form short-lived excited molecules which release energy by light emission as the constituents return to the ground state. Krypton-fluorine excimer lasers produce high-power ultraviolet light used in eye surgery. Other applications are sterilization of fluids and lithographic fabrication of semiconductors. Xenon has a light spectrum that is much wider than neon or krypton and Xenon, with an overall bluish hue that is perceived as being similar to "daylight". It is used in high-intensity aviation approach lights, in high-efficiency incandescent bulbs for automotive and stage lighting uses, in plasma display panels, in operating room and internal examination lighting, and in ultraviolet lasers. Construction: Argon and Krypton are used as a premium filler gases for high-efficiency dual-pane (and triple pane) windows. Argon is about one-third heavier than nitrogen or dry air, and Krypton is twice as heavy as Argon. They may be used individually or in a mixture.

These heavier filler gases minimize heat transmission by convective movement of the filler gas between the panes of glass. The insulating value of the window (measured by R value) is roughly proportional to the molecular weight of the filler gas, holding other possible construction differences such as the impact of high efficiency (Low E) glass coatings and triple versus dual-pane construction constant. Noise transmission through windows is also reduced as the molecular weight of the filler gas increases. Argon is about 5 times as expensive as dry nitrogen, but so little is used in a window that the benefits of using it are easily justified. Argon has become the preferred gas to use in most multi-paned windows. Krypton costs much more than argon, often about 100 times as much for the same volume. This price disparity is mainly due to the much lower concentration of Krypton than Argon in air. Only a small number of air separation plants process enough air to make production of Krypton economically attractive. Low Temperature Refrigeration: Neon, with a boiling point lower than all the gases except helium and hydrogen, can be used as a very low temperature refrigerant.

On a volume basis, Neon has 3 times the refrigerating capacity of liquid hydrogen and over 40 times the refrigerating capacity of liquid helium. Properties, Applications and Uses of Other Industrial Gases: Element Families - Noble Gases - Kiara Element Families Nobles Gas is a nonmetal element. : 3- 5 Characteristics #1. 8 valence electrons #2. Noble gases are unreactive #3.As the electricity runs through the gas, ... If you run enough current through the gas, then the light will be constant. ... was very quickly discovered that the other noble gases, such as helium, ... He- Helium Ne- Neon Ar- Argon Kr- krypton Xe- xenon Rn- Radon Nobles Gas is a nonmetal element. : 3- 5 Characteristics #1. 8 valence electrons #2. Noble gases are unreactive #3.As the electricity runs through the gas, ... If you run enough current through the gas, then the light will be constant. ... was very quickly discovered that the other noble gases, such as helium, ...

Noble Gas Family A Glass Globe Filled With Noble Gases {} A Glass Globe Filled With Noble Gases Real World Applications The six noble gases each have common uses in a variety of areas. Helium's low density and stability has led to its use in lighter-than-air balloons. Neon is commonly used in glass-tube neon signs. Argon, on the other hand, is used in ordinary lightbulbs, and also in welding to provide an inert atmosphere. Krypton and xenon have applications in commercial lighting; both are used in flashing stroboscopic lights used on airport runways. Radon, due to its radioactivity, is used in medical treatments such as radiotherapy. The six noble gases each have common uses in a variety of areas. Helium's low density and stability has led to its use in lighter-than-air balloons. Neon is commonly used in glass-tube neon signs. Argon, on the other hand, is used in ordinary lightbulbs, and also in welding to provide an inert atmosphere. Krypton and xenon have applications in commercial lighting; both are used in flashing stroboscopic lights used on airport runways. Radon, due to its radioactivity, is used in medical treatments such as radiotherapy.

Real World Applications Facts About Noble Gases They are generally chemically inert. This means that they do not react with other elements because they already have the desired eight total s and p electrons in their outermost (highest) energy level. The elements in this group are helium, neon, argon, krypton, xenon, and radon. They are monatomic gases. They are generally chemically inert. This means that they do not react with other elements because they already have the desired eight total s and p electrons in their outermost (highest) energy level. The elements in this group are helium, neon, argon, krypton, xenon, and radon. They are monatomic gases. Facts About Noble Gases Element-Hydrogen HYDROGEN / NOBLE GASES 1.

Hydrogen and the Noble Gases (ISBN 1-869860-79- 9) Contents: Introduction; Hydrogen in the stars; How hydrogen bonds; Hydrogen in water; Preparing hydrogen gas; Manufacturing hydrogen; Hydrogen for ammonia; Acids; Testing for acidity (pH); Hydrochloric acid; Sulphuric acid; Nitric acid; Carbonic acid; Organic acids; Bases; The reaction of acids with bases; The reaction of acids with metals; The noble gases; Helium and neon; Argon, krypton, xenon and radon; Key facts about hydrogen, helium, argon, xenon, krypton, neon and radon; The Periodic Table; Understanding equations; Glossary of technical terms; Index Hydrogen Hydrogen (chemical symbol H), named after the Greek word for "water-forming", is the most abundant element in the Universe. In fact more than nine-tenths of all atoms are hydrogen atoms. It is the stuff of stars, of cold "empty" space and of the Earth. Hydrogen is found everywhere and in most compounds. It is the most universal element. Hydrogen is also the simplest element in existence.

Its atom contains just one proton in its core, and only one electron is associated with it. As a result, hydrogen is a tiny atom. But its simplicity explains why it is so universal: it is the building block from which other elements are made. Although it is so universal, hydrogen is rarely found as a gas on Earth. It makes up only three-quarters of 1% of the mass of the planet. This is because hydrogen molecules (combinations of two hydrogen atoms, described by the symbol H2) weigh so little that they can escape from the Earth's atmosphere. The only free hydrogen that survives is in pockets deep underground, part of the decay process that also forms oil and natural gas. Hydrogen is a gas that easily catches fire and can be explosive. Yet it is made in huge quantities each year. About half of it is used to make ammonia (a compound of nitrogen and hydrogen), which is the basis for many fertilisers. About one-third of the hydrogen produced is used in refining metals. Another main use of hydrogen is to make a liquid called methanol, one of the starting materials in making artificial fibres. Helium Helium (symbol He) is another element with a simple structure.

It is the second most abundant element in the Universe, and yet its presence was not suspected until relatively recently. It is the only element ever to have been identified in space before it was found on Earth. Scientists noticed a mysterious element they could not identify in the light shining from stars. Eventually this was identified as helium. Helium, like hydrogen, is lighter than air. But it is an inert gas, which means it rarely reacts and cannot burn. Being inert, it is not found in any compounds on Earth, which is why it took so long to identify. But being an inert gas also means it can be used in places where hydrogen would be dangerous. Thus, helium, rather than hydrogen, fills the floating balloons seen at funfairs. Helium is one of a group of inert, or noble, gases, whose physical and chemical properties are closely related. The other noble gases, which together make about 1% of the Earth's atmosphere, are neon, argon, krypton, xenon and radon. All other elements react to form stable substances. The noble gases are unreactive because they each have just enough electrons to be perfectly stable on their own, without needing to react with other elements.

The noble gases The noble, or inert, gases are helium, neon, argon, krypton, xenon and radon. They make up a complete group (0) in the Periodic Table and the properties of each member of the group are closely related to the others. The noble gases make up nine-tenths of 1% of the volume of the Earth's atmosphere. The noble gases are called inert gases because they do not usually react with any other element. Most elements react with one another because the combined atoms are more stable than the individual atoms. In fact, the most stable state generally occurs when the number of electrons in the outermost shell of an atom is eight. Reactions occur so that atoms can achieve eight electrons, either by losing electrons or gaining them from their partner. The noble gases are so stable, and react so little because, unusually for elements, the number of electrons in the outer part of the atom completely fill the shell. In all but helium the number of electrons in the outer shell is eight; for helium it is two ­ the maximum possible in its only shell. Not all of the noble gases are equally stable. For example, xenon can be made to combine with a few other elements, but helium combines with none.

Hydrogen in water Water is the most common chemical compound on the surface of the Earth, covering over two-thirds of the Earth's surface. People are also about two-thirds water. Water is a compound of hydrogen and oxygen. Although we are so familiar with the way water behaves that we take it as normal, water, in fact, behaves differently from most other compounds. This is due to the strong attraction that each water molecule has for others. Water shrinks as it is cooled (down to 4°C) and then expands as it is cooled further still (to 0°C). It is also the only common substance that swells as it freezes. All these unusual properties are due to the special way that the hydrogen atoms link water molecules together, the property called hydrogen bonding. The atoms that make up water molecules are bound together very much more firmly than are the molecules to each other. Enormous amounts of energy are needed to break them apart. Heating, for example, only changes the physical state of water, converting solid ice to liquid water and then to steam. Only electrical energy will break bonds within the molecules. The process of decomposing water (breaking it apart) is called electrolysis.

How electrolysis works Pure water is a poor conductor of electricity. But water with impurities in it does conduct. Dilute solutions of acids, for example, are excellent conductors of electricity. Dilute sulphuric acid is used in vehicle batteries. If two electrodes are dipped in a dilute acid solution, the electrical energy will break apart the hydrogen particles (ions) from the hydroxyl ions (pairs of hydrogen and oxygen particles). Because opposite charges attract, positively charged hydrogen ions drift through the dilute acid to the negative electrode. There they form hydrogen gas. Negatively charged hydroxyl ions drift to the positive electrode where oxygen gas forms. The production of hydrogen gas from water comes at a price. Large amounts of electricity have to be used. However, the energy is not wasted, but simply stored in the hydrogen gas as chemical energy. This energy makes hydrogen gas very inflammable and even explosive if mixed with air or oxygen. The demonstration on the pages of the Hydrogen book in the Elements set uses electrolysis to collect hydrogen and oxygen gases separately. The equipment is called Hoffman's voltameter. Preparing hydrogen gas Hydrogen gas can be produced in the laboratory by reacting a dilute acid with a metal.

The demonstration below uses dilute hydrochloric acid and zinc. Dilute copper sulphate has been added to the hydrochloric acid to speed up the reaction; this is what makes the acid green. The copper does not take part in the reaction; it is a catalyst. What the apparatus does Hydrogen is produced by the reaction in the flask. The gas is then led through tubing into a water bath containing a gas jar supported on a beehive shelf. This is the standard way of collecting gases that are not soluble in water. As the gas bubbles through it, the water is displaced but the gas is contained. At the end of the experiment a cover slip can be placed on the open end of the gas jar while it is still under water, thus sealing the gas in the jar. EQUATION: Laboratory production of hydrogen Hydrochloric acid + zinc = zinc chloride + hydrogen 2HCl(aq) + Zn(s) = ZnCl2(aq) + H2(g) Noble gases facts, information, pictures | Encyclopedia.com articles about Noble gases Isolation of the Noble Gases HELIUM.

Helium is an unusual element in many respects—not least because it is the only element to have first been identified in the Solar System before it was discovered on Earth. This is significant, because the elements on Earth are the same as those found in space: thus, it is more than just an attempt at sounding poetic when scientists say that humans, as well as the world around them, are made from "the stuff of stars." In 1868, a French astronomer named Pierre Janssen (1824-1907) was in India to observe a total solar eclipse. To aid him in his observations, he used a spectroscope, an instrument for analyzing the spectrum of light emitted by an object. What Janssen's spectroscope showed was surprising: a yellow line in the spectrum, never seen before, which seemed to indicate the presence of a previously undiscovered element. Janssen called it "helium" after the Greek god Helios, or Apollo, whom the ancients associated with the Sun . Janssen shared his findings with English astronomer Sir Joseph Lockyer (1836-1920), who had a worldwide reputation for his work in analyzing light waves.

Lockyer, too, believed that what Janssen had seen was a new element, and a few months later, he observed the same unusual spectral lines. At that time, the spectroscope was still a new invention, and many members of the worldwide scientific community doubted its usefulness, and therefore, in spite of Lockyer's reputation, they questioned the existence of this "new" element. Yet during their lifetimes, Janssen and Lockyer were proven correct. NEON, ARGON, KRYPTON, AND XENON. They had to wait a quarter century, however. In 1893, English chemist Sir William Ramsay (1852-1916) became intrigued by the presence of a mysterious gas bubble left over when nitrogen from the atmosphere was combined with oxygen. This was a phenomenon that had also been noted by English physicist Henry Cavendish (1731-1810) more than a century before, but Cavendish could offer no explanation. Ramsay, on the other hand, had the benefit of observations made by English physicist John William Strutt, Lord Rayleigh (1842-1919).

Up to that time, scientists believed that air consisted only of oxygen, carbon dioxide, and water vapor. However, Rayleigh had noticed that when nitrogen was extracted from air after a process of removing those other components, it had a slightly higher density than nitrogen prepared from a chemical reaction. In light of his own observations, Ramsay concluded that whereas nitrogen obtained from chemical reactions was pure, the nitrogen extracted from air contained trace amounts of an unknown gas. Ramsay was wrong in only one respect: hidden with the nitrogen was not one gas, but five. In order to isolate these gases, Ramsay and Rayleigh subjected air to a combination of high pressure and low temperature, allowing the various gases to boil off at different temperatures. One of the gases was helium—the first confirmation that the element existed on Earth—but the other four gases were previously unknown. The Greek roots of the names given to the four gases reflected scientists' wonder at discovering these hard-to-find elements: neos (new), argos (in active), kryptos (hidden), and xenon (stranger). RADON.

Inspired by the studies of Polish-French physicist and chemist Marie Curie (1867-1934) regarding the element radium and the phenomenon of radioactivity (she discovered the element, and coined the latter term), German physicist Friedrich Dorn (1848-1916) became fascinated with radium. Studying the element, he discovered that it emitted a radioactive gas, which he dubbed "radium emanation." Eventually, however, he realized that what was being produced was a new element. This was the first clear proof that one element could become another through the process of radioactive decay. Ramsay, who along with Rayleigh had received the Nobel Prize in 1904 for his work on the noble gases, was able to map the new element's spectral lines and determine its density and atomic mass. A few years later, in 1918, another scientist named C. Schmidt gave it the name "radon." Due to its behavior and the configuration of its electrons, chemists classified radon among what they continued to call the "inert gases" for another half-century—until Bartlett's preparation of xenon compounds in 1962.

Presence of the Rare Gases on Earth IN THE ATMOSPHERE. Though the rare gases are found in minerals and meteorites on Earth, their greatest presence is in the planet's atmosphere. It is believed that they were released into the air long ago as a by-product of decay on the part of radioactive materials in the Earth's crust. Within the atmosphere, argon is the most "abundant"—in comparative terms, given the fact that the "rare gases" are, by definition, rare. Nitrogen makes up about 78% of Earth's atmosphere and oxygen 21%, meaning that these two elements constitute fully 99% of the air above the Earth. Argon ranks a distant third, with 0.93%. The remaining 0.07% is made up on water vapor, carbon dioxide, ozone (O3), and traces of the noble gases. These are present in such small quantities that the figures for them are not typically presented as percentages, but rather in terms of parts per million (ppm). The concentrations of neon, helium, krypton, and xenon in the atmosphere are 18, 5, 1, and 0.09 ppm respectively. IN THE SOIL.

Radon in the atmosphere is virtually negligible, which is a fortunate thing, in light of its radioactive qualities. Few Americans, in fact, even knew of its existence until 1988, when the United States Environmental Protection Agency (EPA) released a report estimating that some ten million American homes had potentially harmful radon levels. This set off a scare, and during the late 1980s and 1990s, sales of home radon detectors boomed. Meanwhile, the federal government increased concerns with additional reports, advising people to seal their basements and ventilate their homes if radon exceeded certain levels. A number of scientists have disputed the government's claims, yet some regions of the United States appear to be at relatively high risk due to the presence of radon in the soil. The element seems to be most plentiful in soils containing high concentrations of uranium. If radon is present in a home that has been weather-sealed to improve the efficiency of heating and cooling systems, it is indeed potentially dangerous to the residents. Chinese scientists in the 1960s made an interesting discovery regarding radon and its application to seismography, or the area of the earth sciences devoted to studying and predicting earthquakes.

Radon levels in groundwater, the Chinese reports showed, rise considerably just before an earthquake. Since then, the Chinese have monitored radon concentrations in water, and used this data to predict earthquakes. EXTRACTING RARE GASES. Radon, in fact, is not the only rare gas that can be obtained as the result of radioactive decay: in 1903, Ramsay and British chemist Frederick Soddy (1877-1956) showed that the breakdown of either uranium or radium results in the production of helium atoms (beta particles). A few years later, English physicist Ernest Rutherford (1871-1937) demonstrated that radiation carrying a positive electrical charge (alpha rays) was actually a stream of helium atoms stripped of an electron. Many of the noble gases are extracted by liquefying air—that is, by reducing it to temperatures at which it assumes the properties of a liquid rather than a gas. By controlling temperatures in the liquefied air, it is possible to reach the boiling point for a particular noble gas and thereby extract it, much as was done when these gases were first isolated in the 1890s. THE UNIQUE SITUATION OF HELIUM.

Helium is remarkable, in that it only liquefies at a temperature of −457.6°F (−272°C), just above absolute zero. Absolute zero is the temperature at which the motion of atoms or molecules comes to a virtual stop, but the motion of helium atoms never completely ceases. In order to liquefy it, in fact, even at those low temperatures, it must be subjected to pressures many times that exerted by Earth's atmosphere. Given these facts, it is difficult to extract helium from air. More often, it is obtained from natural gas wells, where it is present in relatively large concentrations—between 1% and 7% of the natural gas. The majority of the Earth's helium supply belongs to the United States, where the greatest abundance of helium-supplying wells are in Texas , Oklahoma , and Kansas . During World War II , the United States took advantage of this supply of relatively inexpensive helium to provide buoyancy for a fleet of airships used for reconnaissance. There is one place with an abundant supply of helium, but there are no plans for a mining expedition any time soon. That place is the Sun, where the nuclear fusion of hydrogen atoms creates helium.

Indeed, helium seems to be the most plentiful element of all, after hydrogen, constituting 23% of the total mass of the universe. Why, then, is it so difficult to obtain on Earth? Most likely because it is so light in comparison to air; it simply floats off into space. Applications for the Noble Gases RADON, ARGON, KRYPTON, AND XENON. Though radon is known primarily for the hazards it poses to human life and well-being, it has useful applications. As noted above, its presence in groundwater appears to provide a possible means of predicting earthquakes. In addition, it is used for detecting leaks, measuring flow rates, and inspecting metal welds. One interesting use of argon and, in particular, the stable isotope argon-40, is in dating techniques used by geologists, paleontologists, and other scientists studying the distant past. When volcanic rocks are subjected to extremely high temperatures, they release argon, and as the rocks cool, argon-40 accumulates.

Because argon-40 is formed by the radioactive decay of a potassium isotope, potassium-40, the amount of argon-40 that forms is proportional to the rate of decay for potassium-40. The latter has a half-life of 1.3 billion years, meaning that it takes 1.3 billion years for half the potassium-40 originally present to be converted to argon-40. Using argon-40, paleontologists have been able to estimate the age of volcanic layers above and below fossil and artifact remains in east Africa. Krypton has a number of specialized applications—for instance, it is mixed with argon and used in the manufacture of windows with a high level of thermal efficiency. Used in lasers, it is often mixed with a halogen such as fluorine. In addition, it is also sometimes used in halogen sealed-beam headlights. Many fans of Superman, no doubt, were disappointed at some point in their lives to discover that there is no such thing as "kryptonite," the fictional element that caused the Man of Steel to lose his legendary strength. Yet krypton—the real thing—has applications that are literally out of this world.

In the development of fuel for space exploration, krypton is in competition with its sister element, xenon. Xenon offers better performance, but costs about ten times more to produce; thus krypton has become more attractive as a fuel for space flight. In addition to its potential as a space fuel, xenon is used in arc lamps for motion-picture film projection, in high-pressure ultraviolet radiation lamps, and in specialized flashbulbs used by photographers. One particular isotope of xenon is utilized for tracing the movement of sands along a coastline. Xenon is also applied in high-energy physics for detecting nuclear radiation in bubble chambers. Furthermore, neuroscientists are experimenting with the use of xenon in diagnostic procedures to clarify x-ray images of the human brain. NEON. Neon, of course, is best-known for its application in neon signs, which produce an eye-catching glow when lit up at night. French chemist Georges Claude (1870-1960), intrigued by Ramsay's discovery of neon, conducted experiments that led to the development of the neon light in 1910. That first neon light was simply a glass tube filled with neon gas, which glowed a bright red when charged with electricity.

Claude eventually discovered that mixing other gases with neon produced different colors of light. He also experimented with variations in the shapes of glass tubes to create letters and pictures. By the 1920s, neon light had come into vogue, and it is still popular today. Modern neon lamps are typically made of plastic rather than glass, and the range of colors is much greater than in Claude's day: not only the gas filling, but the coating inside the tube, is varied, resulting in a variety of colors from across the spectrum. Though the neon sign is its best-known application, neon is used for many other things. Neon glow lamps are often used to indicate on/off settings on electronic instrument panels, and lightweight neon lamps are found on machines ranging from computers to voltage regulators. In fact, the first practical color television, produced in 1928, used a neon tube to produce the red color in the receiver. Green came from mercury, but the blue light in that early color TV came from another noble gas, helium. HELIUM. Helium, of course, is widely known for its use in balloons—both for large airships and for the balloons that have provided joy and fun to many a small child.

Though helium is much more expensive than hydrogen as a means of providing buoyancy to airships, hydrogen is extremely flammable, and after the infamous explosion of the airship Hindenburg in 1937, helium became the preferred medium for airships. As noted earlier, the United States military made extensive use of helium-filled airships during the World War II. The use of helium for buoyancy is one of the most prominent applications of this noble gas, but far from the only one. In fact, not only have people used helium to go up in balloons, but divers use helium for going down beneath the surface of the ocean. In that situation, of course, helium is not used for providing buoyancy, but as a means of protecting against the diving-related condition known as "the bends," which occurs when nitrogen in the blood bubbles as the diver rises to the surface. Helium is mixed with oxygen in diver's air tanks because it does not dissolve in the blood as easily as nitrogen. Among the most fascinating applications of helium relate to its extraordinarily low freezing point.

Helium has played a significant role in the low-temperature science known as cryogenics, and has found application in research concerning superconductivity: the use of very low temperatures to develop materials that conduct electrical power with vastly greater efficiency than ordinary conductors. Close to absolute zero, helium transforms into a highly unusual liquid unlike any known substance, in that it has no measurable resistance to flow. This means that it could carry an electrical current hundreds of times more efficiently than a copper wire. WHERE TO LEARN MORE "The Chemistry of the Rare Gases" (Web site). < (May 13, 2001). "Homework: Science: Chemistry: Gases" Channelone.com (Web site). < (May 12, 2001). Knapp, Brian J.; David Woodroffe; David A. Hardy. Elements. Danbury, CT: Grolier Educational, 2000. Mebane, Robert C. and Thomas R. Rybolt. Air and Other Gases. Illustrations by Anni Matsick. New York : Twenty-First Century Books, 1995. "Noble Gases" Xrefer.com (Web site).

< (May 13, 2001). Rare Gases. Praxair (Web site). < (May 13, 2001). Stwertka, Albert. Superconductors: The Irresistible Future. New York: F. Watts, 1991. Taylor, Ron. Facts on Radon and Asbestos. Illustrated by Ian Moores. New York: F. Watts, 1990. Cite this article Pick a style below, and copy the text for your bibliography. MLA The Noble Gases The Noble Gases 222.0 The six noble gases are found in group 18 of the periodic table. They are Helium, Neon, Argon, Krypton, Xenon, and Radon in order of increasing atomic weight. These elements were considered to be inert gases, as they have a closed-shell configuration, until the 1960's, because their oxidation number of 0 prevents the noble gases from forming compounds readily. This was found to be incorrect in 1962 when Neil Bartlett succeeded in making the first complex xenon compound.

His work was confirmed by scientists at Argonne National Laboratory in Illinois, who made the first simple compound of Xenon and Fluorine (xenon tetrafluoride) and latter made Radon and Krypton compounds. Although krypton compounds were made with considerable difficulty, both xenon and radon reacted readily with fluorine, and additional reactions to produce other compounds of xenon and radon could be accomplished. All noble gases have the maximum number of electrons possible in their outer shell (2 for Helium, 8 for all others), making them stable. All of the Noble Gases are gases. The noble gases are all found in minute quantities in the atmosphere, and are isolated by fractional distillation of liquid air. Helium can be obtained from natural gas wells where it has accumulated as a result of radioactive decay. All these gases are monatomic. They boil at low temperatures as only dispersion forces act between the atoms. Helium has the lowest boiling point of any substance at 4.2K. The 1st ionization energy decreases on descending the Group, as the valence shell becomes further away from the nucleus and electrons become easier to remove.

The first ionization energy of xenon is comparable with that of bromine, which explains why xenon forms compounds with oxygen and fluorine relatively easily. The oxidation numbers of xenon in its compounds are +2, +4, +6 and +8. The Noble Gases have important industrial functions. Click on the links to the individual elements to find out more! Krypton, Xenon, and Radon, being the heaviest inert gases, have been known to form chemical combinations as stated before above. This is due to the forces between the outermost electrons of these three elements and their nuclei are diluted by the distance and the interference of other electrons. The energy gained in creating a Xenon or Radon Fluoride is greater than the energy required for promotion of the reaction, and the compounds are chemically stable. Compounds of Helium, Neon, or Argon, the electrons of which are more closely bound to their nuclei, are unlikely to be created. noble gas | Definition, Properties, Uses, & Facts | Britannica.com neon (Ne) Noble gas, any of the seven chemical elements that make up Group 18 (VIIIa) of the periodic table .

The elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og). The noble gases are colourless, odourless, tasteless, nonflammable gases . They traditionally have been labeled Group 0 in the periodic table because for decades after their discovery it was believed that they could not bond to other atoms ; that is, that their atoms could not combine with those of other elements to form chemical compounds . Their electronic structures and the finding that some of them do indeed form compounds has led to the more appropriate designation , Group 18. When the members of the group were discovered and identified, they were thought to be exceedingly rare, as well as chemically inert, and therefore were called the rare or inert gases. It is now known, however, that several of these elements are quite abundant on Earth and in the rest of the universe , so the designation rare is misleading. Similarly, use of the term inert has the drawback that it connotes chemical passivity, suggesting that compounds of Group 18 cannot be formed.

In chemistry and alchemy , the word noble has long signified the reluctance of metals , such as gold and platinum , to undergo chemical reaction ; it applies in the same sense to the group of gases covered here. The abundances of the noble gases decrease as their atomic numbers increase. Helium is the most plentiful element in the universe except hydrogen . All the noble gases are present in Earth’s atmosphere and, except for helium and radon, their major commercial source is the air , from which they are obtained by liquefaction and fractional distillation . Most helium is produced commercially from certain natural gas wells. Radon usually is isolated as a product of the radioactive decomposition of radium compounds. The nuclei of radium atoms spontaneously decay by emitting energy and particles, helium nuclei ( alpha particles ) and radon atoms. Some properties of the noble gases helium polonium (Po) In 1785 Henry Cavendish , an English chemist and physicist, found that air contains a small proportion (slightly less than 1 percent) of a substance that is chemically less active than nitrogen .

A century later Lord Rayleigh , an English physicist, isolated from the air a gas that he thought was pure nitrogen, but he found that it was denser than nitrogen that had been prepared by liberating it from its compounds. He reasoned that his aerial nitrogen must contain a small amount of a denser gas. In 1894, Sir William Ramsay , a Scottish chemist, collaborated with Rayleigh in isolating this gas, which proved to be a new element— argon . Apparatus used in the isolation of argon by English physicist Lord Rayleigh and chemist Sir William … Encyclopædia Britannica, Inc. After the discovery of argon, and at the instigation of other scientists, in 1895 Ramsay investigated the gas released upon heating the mineral clevite, which was thought to be a source of argon. Instead, the gas was helium , which in 1868 had been detected spectroscopically in the Sun but had not been found on Earth . Ramsay and his coworkers searched for related gases and by fractional distillation of liquid air discovered krypton , neon , and xenon , all in 1898.

Radon was first identified in 1900 by German chemist Friedrich E. Dorn; it was established as a member of the noble-gas group in 1904. Rayleigh and Ramsay won Nobel Prizes in 1904 for their work. In 1895 the French chemist Henri Moissan , who discovered elemental fluorine in 1886 and was awarded a Nobel Prize in 1906 for that discovery, failed in an attempt to bring about a reaction between fluorine and argon. This result was significant because fluorine is the most reactive element in the periodic table. In fact, all late 19th- and early 20th-century efforts to prepare chemical compounds of argon failed. The lack of chemical reactivity implied by these failures was of significance in the development of theories of atomic structure. In 1913 the Danish physicist Niels Bohr proposed that the electrons in atoms are arranged in successive shells having characteristic energies and capacities and that the capacities of the shells for electrons determine the numbers of elements in the rows of the periodic table.

On the basis of experimental evidence relating chemical properties to electron distributions, it was suggested that in the atoms of the noble gases heavier than helium, the electrons are arranged in these shells in such a way that the outermost shell always contains eight electrons, no matter how many others (in the case of radon, 78 others) are arranged within the inner shells. Britannica Stories Ringling Bros. Folds Its Tent In a theory of chemical bonding advanced by American chemist Gilbert N. Lewis and German chemist Walther Kossel in 1916, this octet of electrons was taken to be the most stable arrangement for the outermost shell of any atom. Although only the noble-gas atoms possessed this arrangement, it was the condition toward which the atoms of all other elements tended in their chemical bonding. Certain elements satisfied this tendency by either gaining or losing electrons outright, thereby becoming ions ; other elements shared electrons, forming stable combinations linked together by covalent bonds . The proportions in which atoms of elements combined to form ionic or covalent compounds (their “ valences ”) were thus controlled by the behaviour of their outermost electrons, which—for this reason—were called valence electrons .

This theory explained the chemical bonding of the reactive elements, as well as the noble gases’ relative inactivity, which came to be regarded as their chief chemical characteristic. (See also chemical bonding: Bonds between atoms .) Shell atomic model Periodic Table of the Elements Screened from the nucleus by intervening electrons, the outer (valence) electrons of the atoms of the heavier noble gases are held less firmly and can be removed (ionized) more easily from the atoms than can the electrons of the lighter noble gases. The energy required for the removal of one electron is called the first ionization energy . In 1962, while working at the University of British Columbia , British chemist Neil Bartlett discovered that platinum hexafluoride would remove an electron from (oxidize) molecular oxygen to form the salt [O2+][PtF6−]. The first ionization energy of xenon is very close to that of oxygen; thus Bartlett thought that a salt of xenon might be formed similarly. In the same year, Bartlett established that it is indeed possible to remove electrons from xenon by chemical means.

He showed that the interaction of PtF6 vapour in the presence of xenon gas at room temperature produced a yellow-orange solid compound then formulated as [Xe+][PtF6−]. (This compound is now known to be a mixture of [XeF+][PtF6−], [XeF+] [Pt2F11−], and PtF5.) Shortly after the initial report of this discovery, two other teams of chemists independently prepared and subsequently reported fluorides of xenon—namely, XeF2 and XeF4. These achievements were soon followed by the preparation of other xenon compounds and of the fluorides of radon (1962) and krypton (1963). Connect with Britannica Facebook Twitter YouTube Instagram Pinterest In 2006, scientists at the Joint Institute for Nuclear Research in Dubna , Russia , announced that oganesson , the next noble gas, had been made in 2002 and 2005 in a cyclotron .

(Most elements with atomic numbers greater than 92—i.e., the transuranium elements —have to be made in particle accelerators.) No physical or chemical properties of oganesson can be directly determined since only a few atoms of oganesson have been produced. General properties of the group Each noble-gas element is situated in the periodic table between an element of the most electronegative group, the halogen elements (Group 17, the atoms of which add electrons to achieve the octet and thereby become negative ions ), and an element of the most electropositive group, the alkali metals (Group 1, the atoms of which lose electrons to become positive ions). Several important uses of the noble gases depend on their reluctance to react chemically. Their indifference toward oxygen , for example, confers utter nonflammability upon the noble gases. Although helium is not quite as buoyant as hydrogen , its incombustibility makes it a safer lifting gas for lighter-than-air craft.

The noble gases—most often helium and argon , the least expensive—are used to provide chemically unreactive environments for such operations as cutting, welding , and refining of metals such as aluminum (atmospheric oxygen and, in some cases, nitrogen or carbon dioxide would react with the hot metal). The helium-filled balloon Bubble, manned by a scientist … James Aldred/Nature Picture Library Editor Picks: Exploring 10 Types of Basketball Movies The noble gases absorb and emit electromagnetic radiation in a much less complex way than do other substances. This behaviour is used in discharge lamps and fluorescent lighting devices: if any noble gas is confined at low pressure in a glass tube and an electrical discharge is passed through it, the gas will glow. Neon produces the familiar orange-red colour of advertising signs; xenon emits a beautiful blue colour. Neon signs along Nanking Road, Shanghai. Paul Souders/Corbis Noble gases have uses that are derived from their other chemical properties. The very low boiling points and melting points of the noble gases make them useful in the study of matter at extremely low temperatures .

The low solubility of helium in fluids leads to its admixture with oxygen for breathing by deep-sea divers : because helium does not dissolve in the blood , it does not form bubbles upon decompression (as nitrogen does, leading to the condition known as decompression sickness , or the bends ). Xenon has been used as an anesthetic ; although it is costly, it is nonflammable and readily eliminated from the body. Radon is highly radioactive ; its only uses have been those that exploit this property (e.g., radiation therapy ). (Oganesson is also radioactive, but, since only a few atoms of this element have thus far been observed, its physical and chemical properties cannot be documented.) Only krypton , xenon, and radon are known to form stable compounds. The compounds of these noble gases are powerful oxidizing agents (substances that tend to remove electrons from others) and have potential value as reagents in the synthesis of other chemical compounds . noble gases - Student Encyclopedia (Ages 11 and up) Six elemental gases are composed of such exceptionally stable atoms that they almost never react with other elements.

They are the gases that make up Group 0 (the rightmost column) of the periodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). When they were first discovered, these gases were thought to be exceedingly rare and completely inactive; thus they were named the rare gases, inert gases, or noble gases (the term noble, in chemistry and alchemy, had long signified a lack of chemical reactivity). Article Contributors

Question: The Noble gases are Helium, Neon, Krypton, Xenon, Radon and which other element?
Answer: ARGON